OPTIMIZATION OF LACTIC-ACID FERMENTATION OF FROZEN VEGETABLE PROCESS WASTES - MODEL SYSTEMS FOR PRODUCING ANIMAL FEEDS

Optimum conditions for controlled lactic acid fermentation of frozen food processing wastes to produce a stable ensiled feed are described. Parameters used to determine success of fermentation treatments were rapid pH reduction to < 4.55 and rapid acid production. Treatments investigated included: inoculum, Lactobacillus plantarum culture 15A or 2B, L. bulgaricus and Streptococcus faecalis ssp. liquefaciens, and waste fermented. Black-eye peas, potato, green beans, corn and turnip greens represented wastes of different C and N levels. Other treatments included time (0, 1, 2, 5, 12 days), and moisture content (90, 70, 50 and 30%). Moisture level adjustments were made by drying or adding peanut hulls, wheat straw or cardboard. Optimum conditions were culture 15A, 70% moisture obtained by drying or adding peanut hulls (.apprx. 23%) (vol/wt), and C:N ratio of 20-25:1 (10-15% protein). A pH < 4.55 was obtained after 5-12 days with sufficient acidity present to control stability.